The former British colony has been embroiled in more than five months of demonstrations, with pro-democracy protesters angry at perceived Communist Party meddling in a city guaranteed its freedoms when it returned to Chinese rule in 1997.

Protesters are also furious at perceived police brutality, a charge police deny.

Pro-China protesters have gathered before, but in far smaller numbers than those angry at Communist Party rulers in Beijing.

Anti-China students and activists have barricaded at least five campuses in the last week, stockpiling petrol bombs, catapults, bows and arrows and other weapons.

Police have kept their distance for more than two days, but many observers are afraid of what happens if and when they move in.

A 70-year-old street cleaner died on Thursday after being hit on the head by one of several bricks police said had been thrown by "masked rioters". On Monday, police blamed a "rioter" for dousing a man in petrol and setting him on fire. The victim is in critical condition.

On the same day, police shot a protester in the abdomen. He was in stable condition.

Hong Kong returned to Chinese rule under a "one country, two systems" formula guaranteeing its colonial-era freedoms. Protesters' demands include full democracy and an independent investigation into perceived police brutality.

China denies interfering and has blamed Western countries for stirring up trouble. Police say they are acting with restraint in the face of potentially deadly attacks.

Hong Kong universities, in a joint statement, said they regretted the fact that "the government response had so far not been effective".

"However, any demand that universities can simply fix the problem is disconnected from reality: these complicated and challenging situations ... are reflections of Hong Kong-wide disagreement, and the government must take the lead with swift and concrete action."

REUTERS